How can I improve the resistance of ACH550-01 VFD circuit?
All, please help me! I have just installed 2 used XQ1475G CAT generators that have these VFDs radiator fan system in them, However, when the gen goes on the main bus, the overall facility insulation resistance reads low (0.7m0hms). We tested all the components of the gen and got good resistances. When we tested the line-line resistance of the vfd circuit, we got 0.7mohms on the 2 generators but their fan motors are ~40mohms (very good). When we connect the motor directly to the breaker bypassing the vfd circuit, we get fantastic readings and all is well.
My question is: How can I improve the resistance because the VFD circuit plays a great role and cannot/should not be bypassed. Without this improvement, I cannot run the generators.
This question has not yet been answered.